Comet NEOWISE is quietly becoming one to watch

I’ll admit I’ve stopped getting my hopes up about comets. Every year or two there’s a “could be spectacular” candidate that either fizzles, breaks apart near the sun, or stays a binoculars-only object for people with very dark skies. But Comet C/2020 F3, better known as NEOWISE, is starting to look like it might actually be the real deal.

It was discovered on March 27 of this year by NASA’s NEOWISE spacecraft, which is exactly what it sounds like: a space telescope that scans the sky in infrared, originally built to hunt asteroids and comets that could be hazards or just interesting to study. NEOWISE picked this one up while it was still faint and distant, and since then it’s been steadily brightening as it falls toward the sun.

Perihelion, the point of closest approach to the sun, is coming up on July 3. That’s the moment that usually makes or breaks a comet’s reputation. Get too close and you risk the nucleus fracturing under solar heating (we’ve seen that happen before with promising comets that fell apart right when everyone was watching). Survive it intact, and you often get a dramatic brightness boost as fresh ice and dust get blasted off the surface, lit up by the sun.

Early estimates on this one are genuinely exciting. Some researchers are floating the possibility that NEOWISE could become the brightest comet visible from the Northern Hemisphere since Hale-Bopp back in 1997. If you remember Hale-Bopp, you remember it was a naked-eye spectacle for months. That’s an extremely high bar, and I want to be clear this is speculative — comets are notoriously hard to predict, and “could become” is doing a lot of work in that sentence.

Part of the optimism comes from the comet’s size. Estimates put the nucleus at roughly 5 kilometers across, which is a decent chunk of ice and rock. Bigger nuclei tend to be more resilient to the stress of a close solar pass, since there’s simply more material that has to be stripped away before the whole thing disintegrates. It’s not a guarantee — plenty of factors like the comet’s structural integrity and exact composition matter too — but size is generally a point in its favor.

For now, NEOWISE is still too close to the sun in the sky to be easily observed, and the next few weeks around perihelion are the real test. If it survives that pass in one piece, we could be looking at a comet visible in the evening or morning sky in July, potentially even without a telescope. If it doesn’t, well, it won’t be the first comet to promise more than it delivered.

Either way, it’s worth keeping an eye on the astronomy news over the coming weeks. This is exactly the kind of story where the outcome is still genuinely unknown, and that uncertainty is part of what makes it interesting.